Controller for electric motors and similar devices.



No. 855,897. PATENTED JUNE 4, 1907. H. W. LEONARD.

CONTROLLER FOR ELECTRIC MOTORS AND SIMILAR DEVICES.

APPLICATION FILED JULY 11, 1903.

4 SHEETS-SHEET 1 I. A T A. I 51.1.

vv/mzss'es; /NVENTOR A 7 6 w er No. 855,897. PATENTED JUNE 4, 1907. H. W. LEONARD.

GONTROLLER FOR E LBGTRIG MOTORS AND SIMILAR DEVICES.

APPLIOATION FILED JULYll. 1903.

4 SHEETSSHEET 2c.

I. WITNESSES: /NVENTOR Y 2' M 4 No. 855,897. PATENTED JUNE 4, 1907. H. W. LEONARD.

CONTROLLER FOR ELECTRIC MOTORS AND SIMILAR DEVICES.

APPLIGATION FILED JULY 1-1. 1903.

4 SHEETS-SHEET 3.

i i A Q E H W/TNESSES. I a 1 M INVENTOH M d w w (/IEW NO. 855,897. PATENTED JUNE 4, 1907.

H. W. LEONARD. CONTROLLER FOR ELECTRIC MOTORS AND SIMILAR DEVIGBS.

APPLICATION FILED JULY 11, 1903.

4 SHEETS-SHEET 4.

UNITED s TEs" PATENT OFFICE.

CONTROLLER FOR ELECTRIOMQTORSAND s.|m |LAR; oE v|cEs.-r

To all whom it may concern.-

Be it known that I, HARRY WA D LEON- ARD, a citizen ,of the United States, residing at LawrencePark, Bronxville, in the county 5 of \Vestchester and State of New York, have invented a certain new and useful Improvement in Controllers for Electric Motors and Similar Devices, of which the following is a.

specification. IO

vices em lo ed for starting and regulating the spee( electric motors, and to the devices employed for protecting such devices and the motor against damage due to abnorr mal variations in the circuit. Heretofore such devices, and particularly the starters and speed controllers, were. preferably entirely separate pieces of apparatus, and were operated independently of each other. Such 2o arrangements of the controlling devices are fre uentlythe cause of injury to the motor anc controlling means due to the improper operation of the separate devices, and to carelessness or ignorance on the part'of the 2 5 operator.

One object of my invention is to combine a motor starter, speed regulator, and auto matic protective devices with interlocking means, whereby the several elements consti c tuting the controller can only be operated in the proper sequence to start and regulate a motor, and. so that the protective devices will always be in a position to respond to abnormal changes in the motor circuit, and 3 5 whereby the starting of a motor and the control of its speed will be ffool proof, that is to say, the controlling apparatus and the motor will be entirely safe. even in the hands of inexperienced, carelessprignorant operators. In the operation of many kinds of machine tools and other appliances by electric motors, it is very desirable that there be provided a simple, efficient, reliable, inexpensive and compact form of controlling apparatus by 5 means of which the motor can be started and brought to full speed, and later, if necessary,

-' operated at any speed over as wide a range of spee das"poss1ble.. On account of the efliciency and simplicity of the method, it is 50. very desirable to secure the speed variation ,by varying the field strength of the motor,

Electric motors have now been so farim proved as regards freedom from sparking, that they require very little attention in operationteiye'u when the field is varied over a very wide range, andv hence inju'ture these Specification of Iietters Patent. Application filed July 11,1903. Serial N0-'165.0B1-

.My invention relates principally to the de-' Patented June 4, 19o

the operation of machine too and in'permotors willbe very extensively employed in forming many other kinds of work .yvhere a wide range of speed is of value, and-especially where the torque varies inverselyas the speed to such an extent that the power oi; the m0- tor is more or less constant.

The controlling apparatus for suchg,motors should have the following characteristics: First, an overload protective device which Will positively andinstantaneOusIyopen the circuit to 'themotor if under any conditions of starting or operation a current greater than a certain predeterminable amount should flow-in the motor circuit. Second, this overload device must be'such that the motor can be safely and simply started up again by the operator Without loss-of time and without expense.v Third, a, no voltage release or electro-responsive device which Will automatically act if'the supplyv'oltage fails, or isr'educed to a very low :point,.to:-

protect the motor against the risks du. to a sudden rise to full voltage, and suchgffnoi voltage device shall be dependentiiponthe volts upon the motor armature 'and shall. be

independent of any current throughthe II10-{- tor. of which the operator can readily change'the speed of the motor gradually and over a wide range, so that, for example, a cutting tool can be worked in the most efficient manner at any speed and out within the capacity of the motor. Sixth, interlocking or functionally related mechanism, or equivalent arrangement of Inechanism,'which will insure the proper se quence of adjustments, and whereby it will be impossible for the operator to start the motor while the motor has-an improperly. weakened field. While this interlocking or equivalent mechanism is preferably ar ranged directly between the speed controlling device and the motor starter, it is evi- Fourth, a device by the manipulation .85 I

Fifth, a starting rheostat.

ibo

dent that it may be applied betweenan device controlling the speed controller an any device which controls the current passin through the motor armature, such as a switc in series with the motor armature and starter.

The desirable features above set forth are embodied in the controller invente by me "and in carrying my invention into effect'l preferably employ a i no voltage switch and an overload switch, which are functionally connected, and the. no voltage switc serving also as the contact arm of thestart v ing rheostat.

switch is preferably moved to its closed position by the movement of the no voltage switch to its starting position. The overload switch is held closed by a latch which is released through the agency of an electro-responsive device which is set to respond to a predetermined flow of current, and the no voltage switch may be held by asimilar form of latch, which is released through the agency of an electro-responsive device which responds to an abnormal drop in the voltage, or said switch may beheld by magnetism against the pull of the spring connected with said switch, so that when the voltage fails or drops abnormally, the magnetism will be insul'licientto hold the switch against the pull of its spring. I also employ a rhoestat which is designed to be connected in series with the field winding of the motor. This rheostat preferably has a large number of steps so as to secure great refinement in the graduation of the field strength of a motor and thus secure perfect control of the speed of the motor armature. Between the operating devices of the starting rheostat and the field rheostat, I provide in my preferred form an interlooking or otherwise functionally related device, the function of which is to lock the switch arm of the starting rheostat in the initial or open position if the field rheostat is in a position which will producea field too weak to secure the best results in starting the motor. This interlocking device consequently makes it necessary that the operator .should adjust the field rheostat until he secures a predeterminable proper strength, and

the proper adjustment of the field rheostat removes the interlock and permits the operatorto move the armature controlling switch lever to start or control the motor armature. This interlocking device may be a latch which is moved to locking position by the movement of the field rheostat handle in the direction to insert resistance andobtain a weakened field and which latch is unlocked when the handle is returnedto the position of full field strength. Thus if no voltage or overload occurs while the motor has a weakened field, as it would generally have in practice, the switch lever of the starting rheostat when returned to the starting position'would be locked, and before the motor could be started again the operator would first have to readjust the field rheostat to produce afield of predeterminable and proper strength before the circuitis closed at the starting rheostat.

My invention is illu trated in the accom panying drawings in w ich Figure 1 is a lan view of one form of the completecontro ler Fig. 2 is a side elevation thereof; Fig. 3' is a central vertical section thereof; Fig. 4 is a detail view of the locking Both these switches are prefdevice Figs. 5 and 6 are diagrammatic illuserably spring actuated so as to tend to move trations of to the open circuit position, and the overload nections; Fig. 9 is a detail view showing the modified arrangements; Figs. 7 and R are diagrams illustrating circuit conlocking means applied to both the no voltage and overload switches; Figs. 10, 11 and 12 are diagrammatic views showing a reversing controller and functionally related field rheostat and circuit breaker.

Referring to the drawings, A indicates the contact arm of the motor starter and (1. the contact buttons of the resistance sections.

B is the overload switch which enters spring contact blades 1) and which are provided with an auxiliary break b to protect the blades from excessive sparking.

A and B are pivoted on :icommon stud and a spring a coiled around the stud, and having its ends secured. to the switch arms, tends to drive said arms toward each other.

5 is a rubber or other buffer on switch B against which arm A strikes when either arm is propelled by its spring and through which switch B is moved to its closed position by arm A. Switch B is held in its on the switch. the base plate G and is tripped by a plunger (1 which is actuated by a blow from the core of overload solenoid D. The position of this core is adjustable by means of a screw d whereby the overload device will be caused to respond to a predetermined current flow. The no voltage switch or starting lever A is provided with an armature e'which is held by the magnetism of magnet E when the arm is in its final position. Upon an abnormal drop in the voltage, the magnetism of magnet E will be insuflicient to hold lever A against the pull of its spring and hence that lever will return to its initialposition. If an overload should occurswitch B will be released and it will open the circuit and move toward arm A until arrested by the buffer 6'. This opening of switch also denergizes magnet-E and to close switch B against arm A is returned to its starting position-the position shown in the drawing. C is the operating device for the field rheostat, the resistance 0 (Figs. 58) of which is enameled to a metal plate 0 (Fig. 2). This operating device is secured to a shaft 0 which has secured to its opposite end the contact blade device (7 which cooperates with a locking bolt H arranged to slide in guide blocks 71 This bolt is shown in two telescoped sections with a spring h (Figs. 3 and 4) for driving the locking end forward into the path of a shoulder h on contact arm A. The locking placedbetween a pin 72; and one of the bearings h. The position of cam C is such'that be free to retract the bolt and permit the when no resistance a is in circuit spring h will closed position by a latch d engaging pin d This latch is pivoted upon c', On. the shaft 0 is a cam or equivalent 1 bolt as a whole is retracted by spring h operation of contact arm A. When however resistance is inserted and bolt H is pushed forward, the. locking end will stand in the path of shoulder 71 If now arm A returusto its initial position the curved side of shoulder I1 will engage with and depress thelocking end of the bolt against its spring 71 and said end will immediately spring back andstand in front. of shoulder 71 and prevent arm A from being moved away from its initial position. Thus the apparatus will be locked and the motor cannotbe started until the locking bolt withdrawn from the path of shoulder, 72- This is accomplished by re turning handle C to its starting position, i. e. where all field resistance will be cut out, and at which posit-ion the depression on the cam plate will be. under the bolt and. spring 71 will retract the bolt.

The resistance of the starting rheostat is preferably carried on the under side of base (I and em ided in fine sand contained in a cast iron boa l secured to the base plate.

In Fig. 5 I have illustrated modification wherein the contact arm of the starter, or an extension thereof, if so arranged that when it is moved from its final position to the initial position, it engages with the field controller, and operates it so that when the contact arm of the starter reaches its initial position, the resistance of the field rheostat will be all cut out of circuit, thus avoiding the necessity of returning the operating device of the field rhcostat by hand before starting as in-the construction of Fig. 1. In this modification A is the contact arm of the starter, a the resistance, B is the overload circuit breaker switch, C is the operating device of the field rheostat and c the resistance sections thereof. A is the extension on arm A and-C is a pivoted lever having its free arm in the path of movement of eXtension A and the other end is a toothed arc 00 which meshes with spur gear :10 on the shaft of operating device In practice the. contact buttons of a field rheostat are arranged to form alinost a complete circle so that in moving its contact blade from one. extreme to the other the operating device and shaft make nearly a complete revolution. For this reason the toothed are :0 will he provided with the same number of teeth spur gear .r andbe so proportioned, that, in moving device C from one extreme position to the other, arm (1 will move a dis tance corresponding to the angular mov.e ment of arm A from its initial to its final position. ln-the position shown arm AA is in. the final position, and all the resistance of the field rheostat is cut out. Contact arm A and extension A are free to move back and forth without striking lever 0, when no resistance cis in circuit. If device 0 is rotated to cut in resistance, lever C will move toward arm A, and should arm A be released and propelled 'toward its initial position, arm A will enl counter lever C and drive that lever back to its initial position so that the apparatus will be in proper position to again start the motor. It will also be noted that when arm A is in its initial or starting position, as shown in dotted lines, device C cannot be operated to connect resistance into the field circuit of the motor since arm A stands in the path of lever C and locks it and hence device C against movement.

In Fig. 6, I have shown a speed controlling rheostat instead of a motor starter. In some cases it is desirable to obtain the speed variation by a combination of armature controlling means and field controlling means. In this form arm A is a resistance adjusting switch, that is, it is not spring actuated, and instead of holding this armby the no voltage magnet, I provide an additional spring actuated lever F whichcarries the armature for magnet E. When no voltage occurs lever F will be driven toward arm A and drive it to the initial position. In starting, if the field rheostat is in proper position, arm A can be moved forward to close the circuit, and then lever F is moved around to magnet E where it will be held, and arm A may now be adjusted and left at any desired point. If lever F is not held by magnet E, arm A cannot remain in position, since the spring will drive lever F backward and hence arm A to the initial position. The other parts illustrated in Fig. 6 are similar to Fig. 1.

In some cases the motor may have a series winding on the field, so that the field will be affected by the armature current.

I have shown the no voltage coil E in Figs. 5, and 7 as connected across the motor armature terminals with a resistance R in series with it. Sometimes I connect the no voltage coil in series with the shunt field winding of the motor, as shown in Fig. 8, in which case I prefer to use the form in which a solenoid normally sustains a magnetic weight which falls upon the occurrence of no voltags and opens a latch which releases the starting arm as shown in my application filed June 1, 1903, Serial No. 159,528.

In the case of a motor speed controller such as is shown in Fig. 6 and in which the resistance controlling arm is not spring actuated, I prefer to connect the tern inal of the no-voltage magnet circrit to the center stud as is the case in Fig. 4 of 'my Patent No. 585444, granted June 29, 1897, and Figs. 1 and 4 of my Patent No. 719018, granted January 27, 1903, which show speed controlling arms not spring actuated and by such connection the no-voltage magnet is unaffected by the drop in voltage upon the resistance.

In Fig. 7 is illustrated the circrit connections of the controller of Fig. 1. A is the contact arm of the starting rheostat and a the resistance; -B the overload switch; D the overload coil; E the no voltage coil; R the to binding-posts 1-2.

resistance in series therewith; M the motor and c and c the resistance and contact of the field rheostat. The line wires are connected From post 1 the circuit extends through coil D. to switch B, contact arm A and resistance a to posts 3 and 4. The ari'nature of actor M is connected between posts 2 and 3, and the field winding is connected between posts 2 and 4 in series with the field rheostat. The no voltage coilis also connected between posts 2 and 3. From the illustration it will be seen that the armature and field winding are in shunt relation; that the overload coil is in series with both the armature and held crrrent; and

that the no voltage coil is connected across the armatgc re terminals. Fig. 8 is a diagram showing the same connections and parts as Fig. Texcept that the no voltage coil E is connected in series with the shunt field winding of motor M, and in such arrangement a resistance in series with coil E is not neces In Fig. 9 is shown a locking shoulder B on If when resistance is in the field circuit of theirotor andholt II is in looking position and an overload current should flow, switch Bin opening the circizit will be locked open and before the circuit can be closed again at switch B, the field rheostat mt st first be readjt sted to unloclcthe switch.

' In Fig. 10 my invention is shown applied to a reversing controller and in which the reversing controller and field rheostat are functionally related so that the resistance of the controller cannot be cut out except when the field is in a certainfcondition. The armature and field winding of the niotor is indicated at i M. In the main circ'rit is a switch conprising the two spring pressed arn's A, B, the current passing from one supply terminal throughthe overload solenoid D, which may act to release arm B and open the circuit, then through arnis B and A through the reversing controller and npotor arntature to the other supply terminal. (h rrcnt also passes independently from one side of the line through the resistance R and retaining magnet E to the other side, and there is likewise a ClICTlt across the line including the field of the niotor, the field resistance 0 and the field rheostat arm The n'ovable clement oi the reversing controller comprises an arm A- electrically connected to one side oi the line and engaging one or the other of two contact segments Z connected to the teririnals of the motor armature. The movable elen'ent also includes an insulated conducting portion /..-f which electrically connects the contact segments Z with the concentric outer strips in and the contacts m of the controlling resistance. 1 The operating shaft of the controller carries a cam n on which rides one end of a rod 0 connected to the field rheostat arm 0 a spring 8 on arm attending to force the rod rheostat in. proper condition. shown a double pole circuit breaker htving against the cam. The position of the arm 0 is consequently determined by the position of the'reversing controller. T he off position of the controller arm is a vertical one with the part is downward. S1 ppose the circuit breaker to be closed and that the controller arm is trrned from the oil position so that the part 7r engages the contacts at the right. The current will then pass from say positive line to right-hand segment m. throi'gh the 31111511111? resistance to part. 11, segment Z, motor armatr re, left-hand segment 7, arm 7; to negative line. As the arm is rotated lefthandedly, the arn'iature resistance will be gradually out out and will be all cut out when A" engages segment mi Di ring this operation, the rod 0 has remained ate; ts lowest po sition by pressure of spring 5 and all field re' sistance has therefore been cut out giving a strong field. Upon frrther movement of the controller, the rod 0 ridesv upon an inclined portion of cam ll, causing field-resistance to be gradually cut in giving a further increase in the speed of the motor. This condition is illustrated in the figure. Iinow it is desired to reverse the motor, the controller arm will be turned in a right-hand direction, which first cuts out the field resistance, then cuts in the armature resistance and then breaks the arinatrre circuit. Continring the movement brings the part I." in contact with the left-hand contacts and part it in contact. with the right -hand segment Z. Current then passes through the armature resistance and arinatrre in the opposite direction giving reversal in rotation. Further movement of the. controller arm cuts out the armature resistance while the field is maintaii'ied at full strength and afterward weakens the field as previously explained.

In Fig. 11 I have shown a reversing controller, field rheostat and circuit breaker all functionally related so that the circuit breaker cannot be closed except when the reversingcontroller is in proper condition and the resistance of the reversing control er cannot'be cut cut exccpt when the field I have spring pressed imlepcndentlv movable arms each 'adapted to be held in position by' mechanical restraining means, as by latches t.

The arms are released by the upwardmovement of theccrc of the overload solenoid I), or the left hand arm ,1) is released by the fall of the core of the no-voltage solenoid E which is connected across the line in series with a resistance It. The reversing controller is shown as made up of the two contact segments Z and two outer series of resistance contacts m, over which moves the controller arm comprising the part 7i? which contacts with segments land is connected to one side of the line, and the part A." which makes a connection trom segments Z to the contacts m. The segments Z are connected to the motor armature terminals and the two u per' contacts rm to one side of theline'.

shown in Figs. 3 and 4. Mechanically con ounted upon the controller shaft is a circularplate 51 having a recess q in one part thereof. 'Arod is forced against said plate as by a spring 71- and carries a projections adapted to engage a notch 'v in one of the circuit breaker arms 1)., The rod 0 has a yield able section as indicated at 0 similar to that nected withthe shaft of the reversing controller, as by the extended shaft to "is a cir- This notch is cular plate g having a notched portion 9 rod a: which has a yieldable portion 0 and is pressed downward as awhole'by spring h I I shown inzheir open position and the arms of .fwere'in any other than off position, the rod 0 would be raised from the notch of plate qand projection 0 would engage the'notch-v preventing the-closing of one arm of the circuit Y breaker. Also if the'field resistance arm were in any'position other than that in which all resistance is cut out, the rod'm would be raised and engage the notch g preventing the not be closed unless thereversing controller The circuit breaker switch -to open the main circuit at contacts with the armature resistance in and the fiel one turning the"r,eversing' controller movement of the reversin controller as start the motor; unless the' eldhas its full strength. a'efore the circuit breaker canis in off position and "the circuits of the reversing controller cannotbe closed 'unless the.

field resistance is'o'ut of circuit? Startin resistance .out is. consequently imperative. n the 'reversm'g' controller 18 turned in direct on from ofl and the armature :currentis in the opposite direction.

In, Fig. 1-21 have also shown an inter I locked or functionally related reversing con-f troller,' field rheostatand-1circuit breaker.

is shownin'i'the form of a pivoted switch B; spring pressed by spring 3 at itsflp'ivot' so as to tend to'move the 3]. 'ivoted' latch d? tends normally to engaget e i d"v when the switchis in' the .1closedposltion-andto hold the same closed.

plunger for tripping. the latch is shown as .having two iron cores.

by' jthe: icdiljEf 'wlii'ch forms a circuit across 'the line iifseries with a resistance. R through g it hmgandcontacts yandnormally tends adapted to receive one end oiia tion shown, which is the position, current p'asses through the armatureiri one direct reversed byv b One is acted upon .turned to ofl to hold the plunger up and which, upon 00- currence of no-volta e, permits the plunger to fall and trip the etch (Z? and allows the circuit breaker to be opened by springs. The other core is acted upon by coil D in series in the main circuit and which upon the occurrence of overload is adapted to draw the plunger down to trip latch d and open the circuit. v

The reversing controller is provided with the contact segments Z, Z, the contact segments 7 5 m, and the resistance contacts m, The controlier arm is provided with an insulated conductor k adapted to engage segments Z and the plate Z and also provided with'an insulated conductor is adapted to connect the '8 segments Zwi'th the segments m or resistance contactsm. The controller arm in the posiotf position, engages an extension B of switch B so as to close the latter. "The plate Z is connected to one' supply line and the segments m are connected to the other supply line through switchjB and contacts y. The segments Z are connected,

I to the armature terminals- The motor field coil is 'shownconnected across the line in st-[ 0 ries. with a variable resistances and arm 0 The arm 0 is pressed by a spring 8 tending to return it to sucha position that no field re-. sistance is included and also'tending to press the rod 0 which is attached to arm 0, against 9 5 a cam n. The cam n is attached to shaft w which is also the shaftof the controller arm."- The shape of the cam '12 is such that in the off position of the controller, rod 0 is in it's lowest-position and all field resistance out .of

circuit. When the controller arm is moved in one direction the armature circuit will be closed through the'starting resistance and when the circuit is first closed the switch B will be 1; 'fre'eto' open automatically upon occurrence of overload or no-voltage since the controller arm will not then engage the projection B As the controller arm is moved, the armature resistance will be gradually cut out and will ro entirely out out when It" makes contact with one of the segments m. U to this position the shapeof cam 'n" is suc that rod 0 remains in its lowest position, but upon further-movement ofthe controller arm, the rod 1 r 5 '0 will he raised and resistance cut in the field circuit. When the controller arm is moved in the opposite direction, a similar action will. take place except that the current through the motor armaturew'ill be reversed. It is :20 therefore apparent that if the,circuit' breaker opens, it can be closed and the motor started again onl by first returning the controller arm .to '0 position and" when the armis 're-,

position, field nesistanc'e will 1 25.

be cutout.

I do not limit myself 'to theslpecific 'disclosures herein shown and descr' ed, as my ward the initial pos'itionand which arm is.

designed to be held in its final position, an automatic release for said arm, which responds when the supply voltage falls below a certain amount, and means for preventing the starting of the motor when the field rheostat is in a position to cause a weakened field.

2. The combination with a motor having a shunt field winding, a rheostat in series with such field winding,- a starting rheostat,,means tendingto move the contact arm thereof toward the initial position and which arm is designed to be held in its final position, an automatic release for said arm which responds when the supply voltage falls below a certain amount, and mechanical means for preventing the starting of the motor when the, field rheostat is in a position to cause a weakened field.

3. The combination witlramotor having a shunt 'field winding, a rheostat in series with such field winding, a starting rheostat, means tending to move the contact arm thereof to- Wardthe initialposition, and which arm is designed tobe held in its final position, an automatic release for said arm which re sponds when the supply voltage falls below a certain amount, andgneans for holding said arm against movement fromthe initial position when the field rheostat is in a position to cause a weakened field.

The combination with a motor havin a shunt field winding, a rheostat in series 'Wltll such field winding, a starting rheostat, means tending to move the contact arm thereof toward the initial positionand,which arm is designed to be held in its final position, an automatic release for said arm which, responds when the supply voltage falls below a certain amount, and interlocking means be tween said arm and the operating device of the field rheostat, whereby said arm is held at the initial position when the field rheostat is in a osition to cause a'weakened field. 5.

he combination with a motor having a :shunt field winding, a rheostat in series with such field winding, a starting rheostat, means tending to move the contact arm thereof toward the initial position, electro-magnetically controlled means for holding said arm in its final position, and which means responds to abnormal variations in the motor CJI'Cllit' to effect the release of said arm, and means and for preventing the starting of the motor when the field rheostat is in a position to cause a weakened field.

shunt field winding,a rheostat in series with such field winding, astarting rheostat, means tending to move the contact arm thereof toward the initial position, electro-magnetic-, ally controlled means for holding said arm in its final position, and which means responds to abnormal variations in the motor circuit to effect the release of said arm, and means for holding said arm against movement from the initial position when the field rheostat is in a position to cause a weakened field.

ts. The combination with a motor having a shunt field winding, a rheostat in series with such field winding, a starting rheostat, means tending to move the contact arm thereof toward the initial position, electro-magnetic ally controlled means for holding said arm in its final position, and which means responds to abnormal variations in the motor circuit to effect. the release of said arm, and interlocking means between said arm and the op erating device of the field rheostat, whereby said arm is held at the initial position when the field rhcostat in a position to cause a weakened field. I

9. The combination with a motor having a shunt field winding, a rheostat in series with such fieldwinding, a starting rheostat. means tending to -move the contact arm thereof toward the initial position, an electro-magnet for holding said arm in its final position, and which magnet releases said arm when the supply voltage falls below a certain amount, and means for preventing the starting ofthe motor when the field rheostat is in a position to cause a weakened field.

10. The combination with a motor having a shunt field winding, a rheostat in series with such field Winding, a starting rheostat, means tending to move the contact arm thereof toward the initial position, an clcctroanagnfl. for holding said arm in its final position and which magnet releases said arm when the supply voltage falls below a certain amount,

starting of the motor when the field rheostat is in a position to cause a weakened field.

11. The combination with a motor having a shunt field winding, a rheostat in series with mechanical means for preventing the i such field winding, a starting rheostat, means tending to move, the contact arm thereoftoward the initial position, an electro-magnet forholding said arm in its final position, and

which magnet releases said arm when the. supply voltage falls below a certain amount,

and means for holding said arm against movement from the initial position when the field rheostat is in a position to causea weak-- cned field. i V

12. The combination with a motor having a shunt field winding, a rheostat in series with such field winding, a s1 arting rheostat,

to move the contact arm means tendin ithe initial position, an electhereof towar tro-magnet for holding said arm in its final position, and which magnet releases saidarm rheostat, where'bi;

-when the supply volta e falls below a certain amount, and lnterloc ng means between said arm and the operating device of the field said arm is held at the initial'pos ition w en thefield rheostat 'is in a position to cause a weakened field.

13. The combination of a motor'starting switchand a motor field rheostat jwith means whereby the starting switch cannot be oper-- ated to start the motor except when the'field rheostat is in certain positions.

14. The combinatlon chanical means whereby the starting switch cannot be operated to start the motor except when substantially all the resistance of, the field rheostat is out of circuit.

15. The combination of a motor starting.

switch and a motor field rheostat'ivith inter the contact arm-1 f. the former and the operatingidevice of the. latter, whereby the starting switch cannot be locking means between operated to start the motor except when substantially allthej resistance of the field rheostat is out of circuit.

16. The combination of a motor starting {rheostat and a motor field rheostat with position means for holding the contact arm of they starter against movement from the initial when. the field rheostat is in apos'itionto cause a weakened field.

17:. T he combination of a motor starting rheostat and a motor field rheostat with me-. chanlical means forholding the contact arm of the starter against movement from the initial position when the field rheostat is ina position to cause a weakened field.

rheostat and a motor field rheostat with interlocking means between the contact arm of the'former and the operating device of the latter for holding the contact arm of the starter against movement from the initial position when the field rheostat is in a position to cause a weakened field;

19. [he combination with an electric motor having a field winding supplied from a constant-electro-motive force source, of a of a motor starting 'Switch and a -motor field rheostat withme- 18. The combination of a motorstarting rheostat for varying the field strength of the motor to vary the speed, a rheostat in series with the armature for starting the motor, and means whereby, the starting current cannot be passed through the armature except when the resistance in the field circuit is practically all cut out, so that the motor field is fully ex cited when the motor starts.

20. 'The combination with an electric motor having a field winding sup lied from a source of electro-motive force, 0 a field rheostat for varying the strength of the field, a .rheostat in series with the armature, a novbltage release device for protecting the armature circuit in case of no-voltage, an overload circuit breaker for rotecting the arma ture circuit in case oi means for preventin the closure of the circuit breaker when t ere is no resistance in the armature circuit, and means for preventing the starting up of themotor armature except when the motor field is at a proper strength.

21. The'combination of a field rheostat for varying the speed ofa motor upon a constant electromotive force circuit, and means for preventing the passageof the startin current through the' motor armature when the motor 'eld rheostat is in a certain osition.

22. The combination waii a motor operating upon a constant electromotive force cirof the motor for thepurpose of increasing its speed, and means for preventing the starting up the motor when the field is in the weakened condition.

- f" 23.,The combination with a direct current -motor operating upon a constant electromotive circuit, means or varying the speed of the motor, separate means for starting the motor, and means for preventing the starting of in the position corresponding to the maximums eed. I f

24. a motor controller, the combination ofarhcostat designed 'to-con'trol the armature circuit, a rheostat designed to control sure of the armature circuit under certain predetermined C-OIld1t10nS.-

ture circuit, a rheostat desi ned to control the field circuit, and interloc tween'thetwo rheostats wherebythe armature rheostat is held to. prevent the closure of.. the armature circuit when the field rheostat 1s m a certain predetermined position.

of a-rheostat designed to control the armaturc circuit, a rheostat designed'to control the field circuit, an automatic circuit breaker responding to abnormal conditions in the circult, and means whereby the circuit breaker the motor when the speed varying means is the field circuit, andmeans whereby the armature rheostat is held to prevent the ole-'- ing means be- 26. In a motor controller, the combination excessive current, i

cuit, means for weakening the field strength a IIC 25. In a motor controller, the combination of a rheostat designed to c'bntrol the arma- I torquewithout undue sparking.

isheld against cl .isure until the field rheostatfield rheostat so arranged that the motor is adjusted so as to give the motor a field of proper strength to produce the starting 27. -In a nioti'rcontroller, the combination of a rheost'at designed to control the arinature circuit,- a rheostat designed to control the field circuit,'an automatic circuit breaker responding to abnormal conditions in the cirio cult, and interlocking means between the circuit breaker and the-field rheostat whereby the circuit breaker is held against closure until the held rheostat is ad usted so as to give the motor a field-of proper strength to produce the startin'g torque without undue sparkingl 28. The Combination of a motor having a 5 field winding energized by a current indef pc'ndcnt'of its armature (FIlIIGIlQ-IIINLHS for controlling the current in said winding, and

' 'ineans adapted to start, stop and vary the speedof the motor, said z-wo. means being independently movable but functionally connected mechanically. 29.. The combination with motor having a to overload current, of. 'fielcl controlling means functionally related to said circuit controller.

35. The combination with a motor and a circuit controller comprising means responsive to no voltage which is not in series with.

the armature current, and means responsive to overload current, of field controlling means functionally related to said controller mechanically. 36'. The combination of an electric motor and a constant elcctromotive force supply circuit, said motor having a field Winding energized by a currentindpendent offthe current through its armature, aiio-voltage" protective device responsive to thcline voltagc solely and independent of thecurrent' through the motor fielder armature and which upon no voltage responds and shunt -lield winding, of incansfnr-cimtrollmg:g tcctsithia 'arm'at'iTre agaiii'stfth'ei'rekstab s the field circuit, means for controlling the arment of the line electromot ve force, and an '30 the field circuit controlling means is in accrtain position. v 30. The combination with a motor having a shunt field winding, of a variable resistance in the field circuit, means for varying the said resistance, means for controlling the armature circuit,- and interlocking means so arran wdthat the armature circuit cannot be made until the field is at its strongest.

31'. The combination with a motor having 40 a shunt field winding, of a resistance in the field-circuit, said resistance being capable of variation, a regulating handle adapted to ,va:y said resistance, means for controlling armature circuit, and means for mterthe lockin said handle and armature circuit c-mtro ling means and preventing the closing (f the armature circuit. until'the motor shunt i eld has its greatest field strength.

32. The combination with annotor havihg 5 ifield winding energized by a current indecndcnt of the armature current, means for a fecting the current in said field circuit, n cans for affecting the current in'the armatLre circuit, and means so arranged that the.

ar nature starting current cannotbe passed through the armature until the field circuit cor trolling means are in a desired position;

The combination of a motor having a shunt field winding, an overload magnetic 0o circLit breaker, a spring actuated resistance conti ollin arm, a no-voltage device, said device. beln responsive solely to the line voltage and independent of the current through the motor armature orr'field, and a the motor, said circuit contaimn independent overload circuit breaker functionally related mechanically to the no-voltagedevicc so that the circuit breaker can be closed only when the no-voltage device is in arotective position.

.37, he combination of an electric motor and a constant electromotiverforce supply circuit, said motor havinga field windl energized by a current independent of the armature current, a. circuit. in parallel with circuit. 4

38. The combination of an electric motor an elecand a constant GlQCLIOHlOiZiVGfOICG supplycircuit, said motor having a field winding c n, ei'gized by a current independent of the armature current, a circuit in parallel with the motor. said circuit containing an elcctro-responsit'e device and a relatively high :resistance, said elcetro-responsive device responding to no voltage to release a spring actuated device which when released, moves and protects the motor armature circuit against excessive current when the line electromotive force is rte-established, and functionally related means for varying the motor field current. T

39. The combination of an electric motor and a constant electromotive force supply circuit, said motor having a field wmchng energized by a current independent or the ar mature current, a circuit in parallel with the motor, said circuit containing an electro-re sponsive device responding to no voltage to release a spring actuated device which when released, moves and protects the motor armature circuit against excessive current when the line electromot-ive force is re-established, means for varying the field strength, and means which insures starting the motor under a field of predetermined strength.

40. The combination of an electric motor having a shunt field windin an electroresponsive circuit controlling device responsive to overload current, an electro-responsive circuit controlling device responsive to no voltage, and a device for varying the field strength of the motor, said latter device being functionally related to at least one of said controlling devicesa 41. The combination of an electric motor having a field Winding energized by a current which is independent of the armature current, mutually independent means for pro-' tecting the motor against occurrence of no voltage and overload respectively, and means for varying the current in said field winding, said latter means being functionally related mechanically to said protectin means.

42. The combination of an e ectric motor, a no-voltage protective device responsive to the line voltage solely and independent of the current in the motor'field or armature, an

overload device responsive to predetermined overload current through the motor, and a speed controlling rheostat for affecting the field strength of the motor functionally related to at least one of said'devices.

43. The combination ofan electric motor, a no-voltage protective device responsive to the line voltage solely and independent of the current in the motor field or armature, and functionally related means for varying the speed of the motor by varying the field strength of the motor.

4A. The combination of an electric motor, an electro-magneticcircuit breaker in series with the armature of the motor, a rheostat for controlling the field strength of the motor, said circuit breaker and rheostat being functionally related mechanically.

45. The combination with an electric motor, of means for affecting the current in one element thereof, means for affecting the currentin the other element thereof, said two means being correlated and each being independently movableof the other inider certain conditions, and a device for controlling one of said means under certain conditions, said device being responsive to a current othe than the motor armature current.

46. The combination of a device comprising a resistance for controlling the-energy in one element of an electric motor, a second device comprising a different resistance for controlling the energy in the other element of the motor, said devices being functionally re lated to prevent their improper operation, and electro-magnctic means for protecting one element of the motor against two diil'erent abnormal conditions.

47. The combination of an electric motor and a constant electromotive 'l'orce supply circuit, said motor having a field winding energized by a current independent of the armature current, and means for protecting the motor against no-voltage and overload current, said no-voltage means comprising a cir cuit in parallel with the motor, and said circuit containing an electro-responsive device and a relatively high resistance, and said overload means comprising a device in series with the armature current.

48. The combination of an electric motor having a field Winding energized by current whichis independent of the armature current, a controlling device in series with the motor armature, mutually independent. means for protecting the motor against occurrence of no-voltage and overload respectively, and field varying means for speed variation, said latter means being protectivelyrelated to the said device in series with the motor armature.

49. The combination of supply mains, a circuit across said mains containing one (lement of an electric motor and a controlling device, a second circuit across said mains containing the other element of the motor and a controlling device therefor, and a third circuit across said mains containing a protective device for the motor, said protective device being functionally related to one of said controlling devices and said controlling devices beingfunctionally related to each other.

50. The combination of a motor having a field Winding energized. independently of its armature current controlling means for V214 rying the effective electromotive force on the motor armature, independently movable correlated means for varying the eil'ective elec tromotive force on said field Winding, and means for protecting the motor ari'naturc against no-voltage and against overload current. I

51.- The combination of an electric motor,

IIO

means for varying the speed of the motor by motor, and independently movable Iunctronmotor and independently movable functionally related means ior protecting the 34111131:-

' 5!). The combination of a translating decurrent.

the motor armature and on a field Winding. of the motor, an electro-responsive protective device, said device being energized by a current independent of thecurrent in the armature or Iield, and an electro-responsivc protective device in series with the motor armature. i

53. The combination. of an electric motor, speed controlling means ali'ecting thehrmature Winding, speed controlling ineans affect ing the field Winding, and electro-responsive means or protecting the motor upon occurrence of overload and no-voltage, said novoltage means being responsive to a current other than that passing through the motor armature winding or-that passingthfough the motor field winding.

' 54. The combination of an electric motor, means for varying the speed of the motor by varying the effective electrmnotive force on its armature Winding, cor-related independently acting means for varying the speed by varying the ellective electromotive force on its .lield Wiinling, and protective means re sponsive to-abnormal clectrmnotive force on the motor armature and to abnormal current through the motor armature.

55., The combination of an electric motor, a no-voltage protective electro-responsive Winding, a high resistance in series therewith and not in series with the motor armature, and an electro-responsive winding in series With. the motor armature which acts inderesistance thereofwhile the latter member occupies predetermined positions, and a protective electro-responsive winding in series With the latter member.

61. In hand operated motor controlling apparatus, the combination of two movable switch elements in series with each other and with the motor armature, means protectivel |related to said elements lor prewnting a damaging current to iloxv through the armature due to improper manipulation by the operator, at least one of said elements being automatically and protectively moved in response to overload current through the motor armature, a third movable element for controlling the strength of the magnc tic iield ol' the motor, and means for limctionally relating said l icld controlling element and at least one of said armature UOIlL-LOllil'lg elements for insuring the movement of the field controlling element to a proper position before the starting current can be passed through the motor armature. Y

62. In hand operated motor controlling apparatus, the combination of two movable pendently oi the no-voltage winding to proelements, one of said elements being'adaptcd tect the motor armature against overload 56. The combination oi an electric motor, means for varying a resistance in series With the motor armature, fur ctionally related means for varying the lie d strength of the ally related means for protecting the motor armature circuit against overload current.

57. The combination of an electric motor, means for varying a resistance in series With the 'motor armature, functionally related means for varying the field strength of the ture against overload current and against no-voltage. The combination of an electric motor, means for varying the efiective electromotive force upon the terminals of one element of the motor, electro-responsive means not in series with either element of the motor for protecting the motor against conditions due to, failure ol supply electromotive force, and an independent eldctro-rcsponsive means for protecting the motor against overload.

vice, a controlling resistance having a movable element, two independently movable functionally related switches in series with each other, and means whereby the said eleto control the armature circuit and the other the iicld circuit of the motor, means for pro tectively cor-relating said elements for in suring proper field strength. before the armature starting current can be passed through the motor, and a no-voltage protective means comprising a magnetic winding connected in a circuit independent of the armature or field circuit of the motor.

63. In hand operated motor controlling apparatus, the combinationoi two movable elements, one of said elements being adapted tocontrol the armature circuit and the other the field circuit of the motor, means for pro tectively cor-relating said elements for insuring proper field strength before the motor armature starting current can be passed through the motor,.and a no-voltage protective means comprising. a magnetic Winding connected'in a circuit independent of the armature or field circuit of the motor, the armature circuit, field circuit and the circuit containing the novoltage Winding being all in parallel with each other and the current to all three circuits being controlled by at least one of said elements.

64. The combination of an electric motor having a field Winding energized independ ently oh its armature current, a no-voltage protective device for the motor armature energized independently oi"; the armature or IIO izo

field current of the motor, and two resistance controlling movable elements, one adapted to control the motor armature and the other adapted to control the motor field, said two elements being protectively cor-related.

" 65, The combination with an electric motor, of means for gradually increasing the electromotive force upon the armature While maintaining practically the full electromotive force upon the field Winding and for gradually decreasing the electromotive force upon the field winding while maintaining practically the full electromotive force upon the armature, and means for protecting the This specification signed and. witnessed this 7th day of July 1903. l H. WARD LEONARD. l Witnesses:

i FLORENCE PHILBROQK,

HUGO BOEPPLE, Jr. 

